examples: Add d3d11videosink examples for shared-texture use cases

examples: Add d3d11videosink examples for shared-texture use cases

Add two examples to demonstrate "draw-on-shared-texture" use cases.

d3d11videosink will draw application's own texture without copy
by using:
- Enable "draw-on-shared-texture" property
- make use of "begin-draw" and "draw" signals

And then, application will render the shared application's texture
to swapchain's backbuffer by using
1) Direct3D11 APIs
2) Or, Direct3D9Ex + interop APIs

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1873>